4G ready by end of 2004?
2003-6-21 10:09:52
US standards body the IEEE is expecting to have the standard for 4G in place by the end of next year, despite the delays and uncertainties associated with the commercial roll-out of 3G.
The IEEE standard for 4G - 802.20 - will be fixed by the end of next year and will support data rates up to 4Mbit/s with frequencies up to 3.5GHz, according to Rudy Lauwereins, vice-president of IMEC (International Microelectronics Centre) at Leuven, Belgium.
The 4G standard will allow cell-phones to operate from vehicles travelling at up to 250km/hr, and could be based on OFDM, CDMA and multi-antenna techniques.
Lauwereins said, that the industry need a 'system of systems' connecting wireless and wireline telephony with WiFi and satellite communications. "We need a flexible air interface," he said, in order to facilitate seamless hand-overs between different access technologies and to avoid the need to carry around several terminals each complying with different standards.
"You have only 100ms for the arrival time of packets but you can't do a handover in 100ms using the 'break before make' method," said Lauwereins, "a 'make before break' soft handover allows it to happen in 100ms".
He expects it will take five years for the market to introduce a flexible air interface and that the interfaces will eventually be wearable. "We can do it now, but we can't do it with low enough power and it wouldn't be flexible enough and there'd be problems with the quality of service," said Lauwereins.
For handovers between WiFi and wireless phone calls, Lauwereins expects a product to be on the market by the end of this year. "It will have two different digital parts and two different RF parts and a MAC allowing you to switch from one to the other," said Lauwereins. It will come in the form of a PCMCIA card.
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